As a manual breast pump or other which includes a suction pump or other component operated by a user, a type having a deformable sucking portion has been proposed (see Patent Reference No. 1, for example). As illustrated in FIG. 1 of Patent Reference No. 1, a manual breast pump includes a large cup 41 made from elastic material to directly contact a breast of the user, and a shell 43 made from rigid material and disposed outside the large cup 41. When a suction pump 5 is operated with the large cup 41 attached to the breast of the user, negative pressure is generated within the large cup 41. Then, the large cup 41 made from elastic material is sucked toward the breast and thus presses the breast, thereby effectively sucking milk.
Patent Reference No. 1: JP-A-2002-85552 (FIG. 1 and others)